Iran's President Mahmoud Ahmadinejad said Friday that regional nations should fill the security vacuum when the US withdraws its troops from Iraq - but said there was no prospect of sending in Iranian forces. The United States and Iraq have worked on a deal this year to try to ensure Iraqi security but have disagreed on timing for American troops to withdraw. Iraq has insisted on a timetable but US President George W. Bush has refused to accept one. "The United States will soon leave the region, then regional countries should fill the security vacuum, there is no need for interference of other countries," Ahmadinejad said on the final day of two-day visit to Istanbul, Turkey's financial and cultural center. US and Iraqi negotiators missed a July 31 target date for completing a security deal amid disagreement over US troop withdrawals. Iraq's Shiite-led government believes a schedule is essential to win approval for a security deal in parliament.